Highly stretchable polyester-based piezoelectric elastomer for simultaneously realization of accelerated regeneration and motion monitoring for Achilles tendon rupture

Accelerated regeneration and motion sensing for Achilles tendon rupture is technological bottleneck that has long troubled both patients and doctors. Compared to traditional treatment, efficient and in-situ electrical stimulation by using piezoelectric materials for Achilles tendon repair is of great potential. However, the reciprocating stretching-recovery motion of the Achilles tendon during the repair process set great challenges for developing materials with integration of high piezoelectricity, stretchability, and biocompatibility to realize simultaneously accelerated repair and real-time motion sensing. In the current study, we synthesized a piezoelectric elastomer for tendon rupture regeneration (PETRR). The PETRR presents an elastic modulus as low as 0.3 MPa and a recoverable strain up to 300 %. These properties enabled PETRR to undergo long-term reciprocating motion accompanying with the Achilles tendon, realizing real-time sensing of tendon rerupture and local temperature changes. The PETRR exhibit good biocompatibility and excellent piezoelectricity to achieve electric stimulations promoting tendon regeneration in a rat Achilles acute injury model, where the behavior function and biomechanical properties were significantly improved comparing to control group. Furthermore, the potential mechanism of PETRR promoting tendon regeneration was investigated by RNA-sequencing, identifying a series of potential targets and signaling pathway for further research. This study indicates that PETRR can effectively monitor tendon condition in real-time and promote tendon regeneration.